Located within the 4-star Hotel Terme Millepini in Montegrotto Terme, Italy, is the world’s deepest pool. It’s called Y-40, The Deep Joy. The name refers to the Y-axis (the vertical one), and -40 meters of depth (that’s 131 feet). It’s about 5 meters deeper than the previous world’s deepest pool, the Nemo 33, in Belgium. Containing 4,300 cubic meters (151,853 cu. ft.) of spa water maintained at a constant temperature of 32-34c (around 90F), you don’t need a wet suit to dive down. And on your way to the bottom you’ll encounter four caves for technical underwater training, as well as a viewing tunnel for curious onlookers. We’re not sure about regular admission prices, but a poster on their website advertises 100 dives for 2,000€, which works out to about $25 a dive.